<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        body {
            /*给body添加的样式页面中所有元素都会继承*/
            font-size: 10px;
        }
        div{
            color: red;
        }
    </style>
</head>
<body>
<div>
    <p>我是p标签</p>
    <span>这是span</span>
    <a href="">超链接</a>
    <h1>这是h1</h1>
</div>

</body>
</html>